1. Field of Invention
The invention relates to a piano key assembly for a pianoforte (grand piano) having weighted keysticks to achieve an improved dynamic response.
2. Description of Prior Art
The technique of keystick balancing for a pianoforte (that is, a grand piano) has seen little change in the past 100 years. The U.S. Pat. No. 633,915 to Smith taught the placement of lead weights within the keystick to balance a key in such manner as to make it properly responsive to the touch of the pianist. More recently, the U.S. Pat. No. 5,585,582 to Stanwood (“Stanwood 1”) teaches a method to determine the proper amount of balance weight to place within a keystick during manufacturing to provide a more uniform feel when playing. The U.S. Pat. No. 5,796,024 to Stanwood (“Stanwood 2”) teaches a method for fixing the amount of balance weight and varying an additional calibration weight to achieve the desired balance. The U.S. Pat. No. 6,096,959 to Davide applies keystick balancing to an upright piano key mechanism with the addition of balance weight to the keystick and the wippen. The U.S. Pat. No. 6,531,651 to Kanemitser et al. discloses a musical instrument key with a means for simplifying the adjustment of weights.
Conventional balancing methods and recent improvements such as these focus on the static balance of the keystick and ignore the effect weigh-off has on the internal inertia of the key. Lead weights placed near the “ivory end” of keystick require the piano player to move the weights a greater distance than if the weight were placed closer to the pivot point (fulcrum). (As used hereinafter, the term “ivory end” of a keystick is intended to denote the end of the keystick that is pressed down by the finger(s) of a piano player, regardless of whether the keystick does or does not have “ivory”, or whether the keystick is or is not associated with a “white” key or “black” key.) Stanwood 2 and Davide, both improvements to the teaching of Stanwood 1, increase the keystick inertia with the addition of more weight. While both may create an instrument with keysticks uniformly balanced, the dynamic performance of the instrument is negatively impacted by the inertia increases.
U.S. Pat. No. 2,031,748 to Vietor discloses a technique for balancing the keys of a piano keyboard by the placement of lead weights in the keysticks. Unlike the other prior art references, this patent is concerned with the placement of balance weights to maximally reduce the inertia of the keys. In particular, this patent teaches the placement of a large weight and small weight immediately adjacent the pivot point of the keystick. While this arrangement does, indeed, reduce the inertia to an absolute minimum, it does not provide sufficient static balance weight for a piano key.